Lamp shade



April 11, 1961 c. H. KOEHLER LAMP SHADE 5 Sheets-Sheet 1 Filed Nov. 2, 1956 April 1961 v c. H. KOEHLER 2,979,606

LAMP SHADE I Filed NOV. 2, 1956 5 Sheets-Sheet 2 Invenror; Charles HK New April 11, 1961 KQEHLER 2,979,606

LAMP SHADE Filed Nov. 2, 1956 5 Sheets-Sheet 5 Hll III "M. Wmmmm"lllllllllllillll lllllflllllllllllllllllfllM InvenTorz.

P 1961 c. H. KOEHLER 2,979,606

- LAMP SHADE 5 Sheets-Sheet 4 Filed NOV. 2, 1956 IHHIIHlllhllllllllllllllllll 2| LL WWW Fig.3.

Invenror:

Figu. J b .6-

April 11, 1961 c, KOEHLER 2,979,506

LAMP SHADE Filed Nov. 2, 1956 5 Sheets-Sheet 5 Fig. V5.

64- I j I @r 5 as i 9 Invenror:

O avles oefuer Y fia A nited States Patent LAMP SHADE Charles H. Koehler, Chicago, Ill. (6938 Crocus Court, Greendaie, Wis.)

Filed Nov. 2, 1956, Ser. No. 620,127

'6 Claims. (Cl. 240-108) This invention relates to improvements in lamp shades, and the like. By the term lamp shades I contemplate to include various forms of such shades which are interposed between the source of light, such as an incandescent lamp, and the viewer, or the area being illuminated by such lamp. Such forms of lamp shades include those of cylindrical form and others which are generally used at this time. The invention concerns itself with the construction and form of such shades and the manner of light treatment between the source of light and the viewer or surface being illuminated, which construction and form are such as to produce greatly improved illumination effects, as well as producing a shade of very beautiful and novel appearance. The beauty and novelty of appearance just referred to are directly associated with and produced by the construction of the shade itself. Furthermore, the features of invention herein disclosed are such that such beauty and novelty of appearance when the shade is illuminated by the lighting of the lamp are very different from those produced when the'lamp is not illuminated. Thus, the construction of the shade is such that very different aesthetic effects are produced when the lamp is illuminated and when it is not illuminated.

In connection with the foregoing it is here noted that although the effects of illumination or lighting of the lamp are very different from those produced when the lamp is not lighted, these differences are enhanced in the ease of shades of cylindrical or curved surface form, the curving of the surface of the shade being related to the manner in which the illumination is transmitted through the shade to the eye of the observer, or to the surface being illuminated. However, I do not intend to limit the protection to be afforded by the present application to shades of non-planar surface form, except as I may limit myself in the claims to follow.

In order that the disclosures made herein may be better understood and their significance better appreciated, I shall first explain briefly certain of the features of construction of such shades, as follows:

The shades of the present invention are formed of what may be termed Venetian blind screening, or material of similar form and characteristics. This screening is formed of parallel narrow slats supported by joining elements which extend across the area of the screening substantially at right-angles to the axes of the slats, the slats being thus supported with their slat planes extending at an angle to the general surface of the screening itself, but generally with the slats not at right-angles to such screening surface. The angle at which the slats are supported with respect to the'general surface of the screening (at the location of any given slat) may vary greatly,

but will generally be between about thirty degrees from the general surface of the screening, to about sixty degrees from such surface, but I also contemplate the use of screening in which the slats are of either smaller or greater angular deviation from the surface of the screening, than the values just above recited.

2,979,606 Patented Apr. 11, 1961 "ice 4 I shall hereinafter disclose the relationship of the angle of the slats with respect to the surface of the screening, and the illumination effects produced by the use of such screening. At this point, however, it is also noted that the spacing between the slats, and the Width of' the slats both affect the illumination effects produced, and these factors in turn are definitely related to the aforesaid angle which the slats bear with respect to the general plane of the screening. Thus all three of these factors, as well as the relatively small thickness of, the slats themselves, influence the illumination efiects which are produced.

One feature of my present invention consists in the construction of the lamp shade by the use of such slatted material, the slatted material being formed into the desired configuration, either cylindrical, or otherwise, and provided with suitable means to support the shade with respect to the lamp itself. I contemplate the use of such slatted material with the slats extended either horizontally, or vertically; and I shall hereinafter disclose both forms of lamp shade construction, that is, horizontal slat and vertical slat, individually, and shall also disclose lamp shade constructions in which both forms of such slatting are combined together to produce combined effects of great beauty and striking appearance. It is, however, noted that when producing the shades from such slatted material, whether the slats be horizontal or vertical, or both arrangements combined together, various novel lighting effects are produced at various areas of the lamp shade when viewed from any point of observation. This is because the light rays are reflected from the successive slats in different directions, and also because when the shade is viewed from any selected-point of observation, some illumination can come from the light source directly towards the observer, being passed between successive slats without reflection from the slat surfaces. I here use the expression that such illumination can come directly towards the observer, not limiting such statement to arrangements in which such illumination may reach the observer without modification, since I also contemplate, when desired, the inclusion of one or more translucent screens in the arrangement so that the light reaching the observer shall be modified by such screen or screens whether such light be transmitted directly towards the observer or be reflected from one or more of the reflecting surfaces. I shall fully disclose this feature hereinafter.

The amount of illumination which can come directly towards the observer between any two successive slats will depend on the width of the light clearance between such two slats. By this term I mean the lateral distance between the outer edge of one such slat and the inner edge of the other such slat as viewed by the observer, and depending on the form and location of the light source. As the eye of the observer is swept across the illuminated shade from one edge of such shade to the other edge, it will generally be found that during the first portion of such sweep no' illumination can come directly towards the observer since the light clearance will be zero, all such direct illumination being cut off due to apparent overlap of the successive slats. As the sweep of the eye is continued a time will come when a very narrow slit will allow a very narrow beam of light to come directly towards the observer. From that point the continuation of the sweep will bring the observers eye successively into line of observation with slatted openings of successively greater light clearances or apparent openings, to a location where such light clearance is of maximum width. As the sweep of the eye continues from such point of maximum light clearance the apparent openings between the successive slats will diminish to a vanishing point, and further sweep of the eye will reveal no further locations where direct illuminiation could reach the observer over as far as the terminal edge of the sweep. Thus it will appear that a peculiar effect is produced when using such slatted form of screen for producing the lamp shades. However, it is also noted that reflections from the slat surfaces act to deliver reflected light from all areas across the width of the shade, the amounts of such reflections depending on the angles of the reflecting slats, the nature of the slat surfaces, the degree of polish, if any, of such surfaces, and various other factors. It is also here noted that such reflected light elements are present in those areas of the sweep above referred to, in which direct illumination could reach the eye of the observer. Thus, as respects such areas, a combined lighting effect is produced to the eye of the observer, being a combination of the direct illumination factor and the reflected illumination factor, at any selected point of the shade.

Now, as will hereinafter be disclosed in full detail, due to the angularity of the slats at any area observed by the observer, it will be found that the terminal cut off points of illumination just explained, one being early in the sweep of the eye, and the other being later and prior to completion of such eye sweep, are not located at equal angular distances from the medial plane of the shade. That is, the location of the maximum light clearance will be found at one side of such medial plane of the shade, and not in registry with such medial plane. Accordingly, it will be observed by the observer that there is a zone of maximum illumination lying to one side or the other of the medial plane of the shade, and it will also be observed by him that within the two terminal cut off points, one at one side of the shade and the other at the other side of the shade, the brightness of illumination due to such light clearance effect will rise from zero at one side of the shade to a maximum, and will then fall to zero near the other side of the shade; and that the two zero locations are not equidistant from their proximate shade edges. These conditions and effects produce lighting effects, and shade illuminations of a very striking and unusual and unexpected nature, and are distinctive of shades embodying my present invention, when the shade incorporates vertically extending slats. It is understood that the maximum illumination just referred to is that illumination due to light coming directly towards the observer, and is supplemental to or imposed on the reflected illumination due to reflections from slat surfaces and like elements.

The disclosures herein after detailed include the provision of the slatted screens and arrangements above referred to.

A further feature of the present invention consists in the provision, in the lamp shade, of two sets of such slats, or two such screens, set in juxtaposition face to face, and with their two sets of slats crossing each other in direction. Generally such crossing is at right-angles, the slats of one screen extending horizontally and those of the other screen extending vertically. With such two screen arrangement it is evident that the light clearances of the two screens will also cross each other, producing small more or less rectangular openings instead of the narrow slat or slit openings produced when only a single screen is used. The effect of such two screen arrangement is that when the light source is illuminated there appear to the observer a pattern of small dots of bright illumination regularly distributed over the area of the shade between the terminal cut-o 1 locations at both sides of the medial line above referred to. These dots of bright illumination are, additionally, superimposed on the dimmer illumination over the greater area of the lamp shade and produced by light reflected from the slats of both kinds, horizontal and vertical. Such effects will be disclosed herein as well as may be possibleunder the drawing restrictions relating to Patent Ofiice drawing procedure.

1 have referred to the provision of translucent screens interposed in the light path between the light source and the slat screens. These translucent screens, when used, may be of selected colors, shades, and hues, and may be either single thickness or two or more thicknesses superimposed on each other, so that the illumination shall traverse both such thicknesses where they occur in the path of light. Such color screens, when used, should be rather thin and very translucent (sometimes transparent), and clear but of the selected hues. Various materials are available from which such screens may be produced, some such materials being synthetic products of well known compositions and manufacturers.

I have referred at various places to the reflecting elfects produced especially by the surfaces of the slats. Conveniently screening satisfactory for the present purposes may be formed of aluminum which has a high reflecting quality for most visible wave lengths, and is of a light or silver-like color itself. Other reflecting surfaces may be produced by the use of screens made from other materials than aluminum, such as copper, brass, and various alloys. These have good reflecting qualities, and are of various hues and shades of color.

In other cases screens made from aluminum coated or plated with various materials, either metallic or synthetic, may be used, for producing various color and refiecting effects from such slats. By such coating operations, also, it is possible to provide very thin transparent coatings of reflecting nature on the slat surfaces, so that additional effects will be produced in such reflections. When such coatings are of transparent, clear material, and very thin, light incident to such reflecting surface will be doubly reflected, once from the outer surface of such coating, and again from the metallic surface on which such coating is applied. Due to the refractive index of the material of such coating a diffraction effect is produced in the reflected light, so that wave lengths of various colors present in the incident light will be reflected as a spectral effect, with consequent production of very beautiful color effects over the surface of the lamp shade when the light source is lighted.

In connection with the foregoing spectral eficcts it is also noted that the light clearances between successive slats at and close to the two terminal cut-off locations are very narrow, so that diffraction efiiects are there produced in the light which comes directly through such narrow openings. Such diffraction effects are supplemental to those already referred to and further enhance the beauty of the lamp shade when it is illuminated by tr e light source.

Conveniently the lamp shades herein disclosed may be produced from commercially available screening, or" which one example is that produced by The Kaiser Aluminum & Chemical Corp., located at Oakland, California. and known as Kaiser Aluminum Shade Screening." Such screening is made from aluminum sheet of thickness approx. 0.0085 inch, and made from what is known in the trade as corrosive resistant 52 S alloy Kaiser Aluminum, processed to full hard temper. This sheet material is die cut and formed to produce the screening in sheet form, with the successive slats approximately 17.5 to the inch (measured in direction normal to the slats), and with such slats formed at 30 to 45 degrees from the plane or surface normal to the surface in which the screening lies. Thus the face to face clearance between successive slats is approximately 0.057 inch minus 0.0085 inch, or approximately 0.0485 inch, when the slats are normal to the plane which includes the screen. However, since the slats are slanted from such plane of normalitv, the clearance between successive slats is reduced substantially in proportion to the sine of the angle by which the slats depart from suchnormality. When the slats lie at an angle of substantially thirty degrees to such normality the clearance between successive slats will be approximately 0.043 inch. This type of screening also includes transversely extending connecting bars or ribs of the uncut and unformed material by which the slats are connected together and the screen is produced in continuous integral form. These connecting bars or ribs are spaced approximately one inch apart, extend normally to the slats themselves, and are approximately 0.10 inch in width. Thus the slats are approximately 0.90 inch in the clear between such bars or ribs.

Another screening material from which lamp shades of the present invention may be produced is made by The Reflectal Corporation, a subsidiary of Borg-Warner Corporation, of Chicago, Illinois. This screening material comprises thin slats, spaced apart and connected together by bronze or steel wires comprising warps, and spaced apart approximately 0.50 inch center to center. The slats are woven into the wires in such manner that the slats lie at an angle to planes normal to the plane of the screening. It is here noted that in the case of such Reflectal screening the slats are continuous through the successive warp wires, whereas in the case of the Kaiser screening each slat terminates at its ends at the proximate bars or ribs. This fact will be referred to hereinafter.

In the drawings:

Figure 1 shows an elevational view of a typical table lamp stand provided with a lamp shade embodying the features of my present invention; and the shade applied to the lamp stand in this figure is provided with two sets of the screening hereinbefore referred to, crossing each other at right-angles, but the light source is, in this figure not illuminated so that only the slats of one set of screen sections (in this case the vertical slat screen) show by reflected light reaching the shade from points external to the shade, with the consequence that the shade presents the appearance of a large number of closely set vertical lineations with intermediate horizontal bands which will be explained hereinafter; and the light source together with the supporting bracket therefor are shown in this figure by dotted lines;

Figure 2 shows an elevational view of the lamp shade of Figure 1, removed from the stand, but provided with the light source which is, in this case illuminated so that the efiects of such illumination are shown in this figure as best possible consistent with requirements of Patent Office practice;

Figure 3 shows a top plan view corresponding to Figures l and 2;

Figure 4 shows an elevational view of a modified construction of lamp shade embodying the features of the present invention, such shade being removed from its lamp stand and its light source being not illuminated so that the appearance of the shade is that produced by reflection of light from its external surface only, the location of the light source being shown by dotted lines;

Figure 5 shows an elevational view of the lamp shade of Figure 4 but with the light source illuminated to show the appearance of the shade under transmitted light produced by the light source as best possible consistent with requirements of Patent Office practice;

Figure 6 shows a half horizontal section taken on the line 6-6 of Figure 5, looking in the direction of the arrows, but on double scale as compared to Figures 4 and 5; and this figure shows the relationship between the vertical screening slats and the lateral locations thereof sidewise'of the shade, when the slats are all faced towards the left and outwardly of the screen; and this figure also shows how the direct illumination due to light transmitted through the openings between the slats finds its area or zone of such direct illumination laterally displaced with respect to the medial line of the shade;

Figure 7 shows, more or less schematically,-how the intensity of illumination of the shade varies as the eye traverses the shade from one side to the other, such light intensity being shown inlumens per unit area on an arbitrary scale;

Figure 8 shows a faceview of a section of typical screening which may be used in the construction of lamp shades embodying the present invention, being screening of the Kaiser Aluminum & Chemical Corp., hereinbefore referred to; and in this figure the slats'are vertical and are such that each slat slants leftwardly and outwardly (from the interior of the shade towards the observer);

Figure 9 shows a face view corresponding to that of Figure 8, but with the slats extending horizontally, and slanting upwardly and outwardly (froni the interior of the shade towards the observer);

- Figure 10 shows a face view corresponding to Figures 8. and 9, but with the two sheets of screening set into juxtaposition and face to face, so that a combination effect is produced when the light source is illuminated to produce the transmission oflight outwardly through the screening slat openings, and according to the principles hereinbefore explained; and in this figure the slats of the two sheets of screening slant as shown in Figures 8 and 9;

Figure 11 shows another face view similar to that of Figure 10, but with the slats of both sheets of screening reversed as compared to the showings of Figures 8, 9 and 10;

Figure 12 shows a fragmentary horizontal section taken on the line 12-12 of Figure 10, looking in the direction of the arrows, and on greatly enlarged scale as compared to Figure 10;

Figure 13 shows a fragmentary horizontal section taken on the line 13-13 of Figure 11, looking in the direction of the arrows, and on greatly enlarged scale as compared to Figure 11;

Figure 14 shows a fragmentary face view of the combination two sheet arrangement of Figure 11, but .on greatly enlarged scale as compared to Figure 11; and this figure shows that with the screening therein illustrated small rectangular openings are left between the slats of the two sheets of screening and through which direct illumination may pass to the exteriar of the lamp shade (not considering the presence of one or more sheets of translucent material combined with the arrangement); 1 v

Figure 15 shows a lamp shade embodying the features of the present invention, and combined with an advertising novelty or display which is to be illuminated from above by direct light coming from the light source;

Figure 16 shows a horizontal section taken on the line 16-16 of Figure 15, looking in the direction of the arrows; and

Figure 17 shows a face view of the back sheet or blank of the arrangement shown in Figures 15 and 16, and this figure shows that a portion of the area of such back sheet is provided with reflecting surface to enhance the effects produced by the assembled arrangement shown in these figures.

Referring first to Figures 8 and 9, I have therein shown two sections of a Venetian blind material such as is suitable for production of lamp shades according to my present invention. The material therein shown is that produced by The Kaiser Aluminum & Chemical Corp., and previously referred to herein; and in these figures the slats and their spacing are approximately double in size from the material referred to. Figure 8 shows such a section of material with its slats extending vertically, whereas Figure 9 shows such section of material rotated substantially ninety degrees in its own plane to bring its slats into horizontal position. Otherwise the two sections shown in these figures are identical. This slat material comprises a thin sheet of metal, generally aluminum or an alloy thereof, die treated and formed to produce the narrow slats 20 extending between transversely extending bars or ribs 21 of such sheet material, with which bars or ribs the'slats are in-' tegral, and which bars or ribs serve to join the end portions of the successive slats together into a continuous fit; integrally formed sheet. In practice such sheet is wide enough to provide for a number or many of the slat sections, that is, the sheet is of width required for a number of slats located end to end, and with the bars or ribs extending lengthwise of such sheet. Thus, in the lamp shade herein described, and shown in Figures 1, 2. and 3, I have made use of a sheet of such material wide enough to provide at least ten of the sections of slats with the intervening bars or ribs. Actually the stock material from which the lamp shades may be made is much wider than such ten slat sections, but manifestly the width of the sheet of raw material may be as needed according to the side of the lamp shade to be produced therefrom. Otherwise, two or more sheets of the slat material may be suitably joined together, edge to edge or otherwise, to provide the sheet width needed for production of the size of lamp shade to be produced.

In the forming operations these slats are rotated from the general plane of the material, so that all of the slats lie in planes parallel to each other but rotated a pre-determined angle from the general plane of the material. In the showing of Figures 8 and 9 the slats have been rotated substantially thirty degrees from such plane. The spacing between the succesive slats is small, and in the material shown in these figures such spacing is of the order of magnitude previously given.

Although Figures 12 and 13 are sections taken on Figures 10 and 11, respectively, I here refer to such Figures 12 and 13 as showing the successive slats in section, and the spacings 22 between them, in the front sheet shown in each of said Figures, 12 and 13. These sections of Figures 12 and 13 also show that the slats are formed at angles with respect to the plane of the material. Accordingly, the face to face clearance between successive slats is reduced substantially in proportion to the cosine of the angle of rotation of the slats from planes normal to the general plane of the material.

It is also noted that the width of each slat measured along its medial line and from front to back, is substantially the same as the spacing between successive slats, since each slat comprises material taken from such spacing. Under these conditions it is also noted that the rear edge 23 of each slat is displaced laterally from its front edge 24 by an amount dependent on the width of such slat and the degree of slat rotation already referred to. Accordingly, there is also produced a lateral displacement of the rear edge 23 of each slat from the front edge 24 of the next adjacent slat in the direction of slant, such displacement being indicated in each of Figures 12 and 13 by the legend 25. Accordingly, when viewing such a sheet of slatted material from a point directly in line with one of such displacements there will appear a clear line of vision of width determined by such clearance.

Next, as the line of vision is shifted laterally to the right in Figure 13, from such directly in line of vision, and without movement of the eyes of the observer other than rock of his eyes towards the right, the clearances between the successive slats will decrease as the angle of vision towards the right is increased. Such decrease in visible clearance will finally result in attainment of a rightward angle at which no clearance exists, but a complete cut-oif occurs, so that the eye as now looking at the slats Will see no clear space between successive adjacent slats located successively farther towards the right from the original line of vision. Since the clearance between the successive slats thus regularly decreases as the angle of vision is increased rightwardly from its original line of vision, the amount of light which may pass directly through the slatted material also decreases as the angle of vision rightwardly is increased, until no illumination can come directly to the eye of the observer from between slats located still farther to the right.

Now, still further considering the slatted material shown in Figure 13, but rocking the observers eye leftwardly we find the following: As such leftward rock occurs the line of vision will come nearer and nearer to alignment with the angle at which the slats lie with re spect to the general plane of the slatted material. Due to this circumstance the apparent width of the clearance will increase until the eye eomes to that leftward angle of vision at which such angle of vision is parallel to the slats, whereupon a maximum apparent opening between the slats will be seen. Thereafter as the angle of vision is rocked still farther leftward (still considering the showing of Figure 13) the apparent width of clearance between the successive slats will decrease until an angle is finally reached at which such apparent clearance becomes zero. At that point no illumination can come between slats located still further leftwardly. It is thus apparent that the location of the maximum apparent clearance between he slats lies, in the case of Figure 13, leftwardly of the direct line of vision. It is also apparent that due to this circumstance, and a complete analysis of the problem mathematically and analytically, the location of the final cut off point rightwardly is much closer to the direct line of vision than is the location of the final cut off point leftwardly of the original direct line of vision. Thus, an apparent unbalance is produced in the amount of light which may come to the eye of the observer from a light source behind screening in which the slats are set at an angle with respect to the general plane of the screen material, which angle is other than ninety degrees.

I avail myself of the foregoing relationship of the angled slats formation of the screening to the location of the maximum apparent opening between the slats, and to the location of the maximum amount of direct illumination which can come to the eye of the observer, for the production of lamp shades of very unusual and novel and intriguing appearances, especially when illuminated from within by the lighting of the source of light of such shaded lamp. It is here now noted that when viewing such a screen solely by light reflected from the front surfaces of such screen, only the vertical slats or fins are readily apparent, with, of course, the connecting bars or ribs. However, as soon as illumination is supplied rearwardly of such screening in strength sufficient to deliver an appreciable amount of illumination through the slats openings, the above peculiar characteristic of displacement of the location of the maximum light transmission to one side of the direct line of vision becomes apparent, and as the shade is observed the observer is intrigued by the fact that the maximum strength of the illumination is not where he would expect to see it, but rather is displaced to one side of the direct line of vision by an amount of displacement sufiieient to command attention. The stronger the illumination thus supplied at the rear side of the screening, the more noticeable is this unexpected and intriguing effect. Furthermore, when a lamp shade embodying the screening of characteristics above explained is lighted, by lighting the source of light behind such shade, there is at once produced a startling change in the appearance of the shade itself, since the illumination coming directly through the spaces between the slats strongly overcomes the previously existing reflected light appearance of the lamp shade, so that it appears as though a dilferent shade had been suddenly substituted in place of the lamp shade previously seen solely by light reflected from the screen surfaces facing towards the observer. I shall consider thisrnatter further hereinafter.

The above discussion has concerned the effects produced y the a t nature f the sla w ethe h scree be planar or curved into circular, elliptical, conical, oval, or other non-planar form in producing the lamp shades. It will be found that when the screening is thus brought into non-planar form the principles above disclosed in respect to the lateral displacement of the medial line of the area of direct illumination are also valid, and that said effects are in fact emphasized in the case of such non-planar shade forms. I shall consider this fact furtherhereinafter.

The bars or ribs -21 and 21 shown in Figures 8 and 9 are substantially fiat and lie within the general plane of the screening. Accordingly, it is possible to bend such screening around an axis or axes substantially parallel to the slats since such bending about such axes merely bends these bars or ribs on lines of bend which lie withintheir confines, it being well understood that such bending may be produced without distortion or rufiling or other unacceptable effects when the bending is produced about lines lying within the sheet of material so bent. Accordingly, it is possible to form a sheet of such screening material into cylindrical form when the axis of the cylinder lies substantially parallel to the slats of the sheet. I avail myself of this fact in producing the lamp shades herein disclosed.

It will also be noted that since these bars or ribs are composed of such sheet material lying in a plane of the screening it is also possible to bend such sheet of screening at the locations of such bars or ribs along lines parallel to such bars or ribs-that is, normal to the slats themselves. But it is not possible to bend a sheet of such screening at locations other than such bars or ribs about lines non-parallel to the slats, without deforming the slats themselves and forcing them to return into the plane of the screening instead of lying at an angle to such plane as the screening is made. That is, considering the section of screening shown in Figure 9, it is possible to bend such screening about lines lying within the bars or ribs, being at right-angles to the slats themselves, to thus produce an enclosure comprised of successive straight chords of a circle, ellipse, oval, or other enclosure. I avail myself of this property of such screening in producing lamp shades in which it may be desiredto include slats which lie horizontal instead of vertical. Since the bars or ribs are relatively close together, being spaced at the order of one inch spacing, it will be seen that a lamp shade of conventional diameter or size may be produced in this manner without the need of producing more than a small angle of bend at the location of each bar or rib. For example, in the case of a lamp shade of ten inches diameter, more or less, there will be about thirty sections of the slatting, and thirty of the bars or ribs around the perimeter of such shade. Accordingly, the bend at each bar or rib will approximate twelve degrees, so that an enclosure is produced comprising fiat sections which lie successively at twelve degrees to each other.

I It is now noted that when the shade is thus produced by so forming the screening that the slats lie horizontal instead of vertical, the slats can be slanted either up or down from back to front of the enclosure. It happens that in the showing of Figure 9 the slats slant upwardly from back to front, but evidently a contrary condition will be produced by merely turning the screening through 180 degrees about an axis normal to the general plane of the screening.

Referring again to the clearance shown at 25 between the front and rear edges of successive slats, it will be evident that by setting two sheets of the screening together face to face, and with their slats at right-angles to each other, one set of slats being vertical and the other set being horizontal, there will be produced small openings directly through both sheets of screening, such openings being located at the points where the clearances of the two sheets come into registry. In Figures 10 and 11 I have shown two sections of such double thickness arrangement, the slats in the two cases being shown as slanting oppositely; that is, in Figure 11 the vertical slats slant oppositely to corresponding vertical slats shown in Figure 10, and likewise in Figure 11 the horizontal slats slant oppositely to corresponding horizontal slats shown in Figure 10. The arrangement shown in Figure 11 is the preferable arrangementfor reasons which will presently appear. Examination of Figures 10 and 11 will thus show the small openings 26 located at the points of registry of the fclearances of the two sheets of screening. In

Figure 14 I have shown, on much exaggerated scale this condition, wherein such openings 26 are very apparent. The existence of these small openings materially affects the appearance of the lamp shade when illuminated interiorly, as the direct illumination coming through these small openings produces a myriad of dots of illumination scattered over that area of the lamp shade embraced between the two lateral cut-off locations discussed earlier in this specification. These dots, being especially noticeable in comparison to the other illumination by reflection, presently discussed, produce a further striking and intriguing appearance to the lamp shade when illuminated, andfurther materially change the appearance of the shade under interior illumination as compared to its appearance when not so interiorly illuminated.

It is also here noted that the bars or ribs 21 and 21 cutoff any direct illumination along lines covered by them. When the double sheet arrangement is used in the production of the lamp shade it will be seen that there are thus produced two sets of such cut-off lineations, such sets lying at right angles to each other, one set being horizontal and the other vertical. Furthermore, it will be seen that such lineations of cut-off for the outer layer or sheet of screening are fully visible by reflected light coming from sources exterior to the lamp shade when such lamps light source is not illuminated, but that the lineations for the inner layer or sheet are only slightly visible from the outside of the lamp shade, when only such reflected exterior light is present. However, as soon as the lamps light source is illuminated so that the effects of such interior illumination are produced a strikingly different effect is produced by the combined effects of the two sets of lineations at right-angles to each other. This result is that there appear at once somewhat shady rather broad bands of darkness, one set of such bands being horizontal and the other set vertical, such bands subdividing the whole area of the exterior of the lamp shade into rectangles of darker shade than the rest of the unit. Then the bright dots of illumination already referred to appear scattered over the surfaces included within such rectangles, producing a strikingly beautiful and novel ap pearance. v The change of appearance of the lamp shade when changing from non-illumination of the lamps light source to illumination thereof, or vice versa, is most impressive, and constitutes an important function in the operation of the lamp shades to which the present invention relates.

Examination of Figures 10 and 11 shows somewhat emphatically the slats of the inner sheet, more definitely in fact than is found in realism. This is, however, due to the fact that the showings of these two figures. as

well as those of Figures 8 and 9 are on substantially -double the size of the actual screening previously referred to herein. The showings of Figures 1, 2, 4, 5 and 15 more nearly convey a correct impression of the actual appearances of the lamp shades under conditions of non-illumination and illumination produced by the light source of the lamp itself; but even these latter figures cannot deliver to the observer a full conception of the actual appearances of the various units. It is here noted that Figures 8, 9, 10 and 11 are on substantially four times the scale used in preparing Figures 1, 2, 4, 5 and 15. I

Referring nowto the showings of such Figures 1, 2

and 3, 4, 5 and 6, and 15, 16 and 17, the lamp shade construction of Figures 1, 2 and 3 includes the two sheet screening arrangement already described, with the outer sheet having its slats vertical and the inner sheet having its slats horizontal. In Figure 1 the lamps light source is non-illuminated, whereas in Figure 3 such light source has been illuminated. Conveniently the lamp shade of these figures includes a circular frame having the top ring=27 to which the upper edge portions of the screening sheets are connected. Both of the screening sheets are brought into generally circular formof cylindrical shape, as shown in Figure 3. The cylinders thus produced are set, one into the other, and they will retain such relationship either vby frictional engagement with each other or by special securing means, not shown. The top ring 27 is secured to the outer ends of a series of arms 28 which extend radially from the central circular plate 29 to which such arms are secured. The shade of Figures 1, 2 and 3 is supported at the top of a lamp stand of conventional form, including the base 30, the upright Ill, and the lamp socket 32. The stems 33 and 34 extend upwardly at the opposite sides of the lamp bulb 35, and the rod 36 extends up from such stems, being provided with the plate 37 at its upper end. The plate 29 is then set down onto the upwardly projecting threaded portion of the rod 36, a cap screw 38 being threaded onto the upper end of such projecting portion, to clamp the plate 29 securely to the rod. Thus the lamp shade is removably secured to the lamp stand in conventional manner.

Referring again to Figures 8, 9, 10 and 11, it will be seen that since the slats are formed by rotating the material from which the screening is made on axes parallel to such slats (to produce the desired angularity of the slats with respect to the general plane of the screening), the bars or ribs 21 and 21 lie in slightly depressed areas 39 of the so-formed screening, the edge portions of the slats extending outwardly in both direc tions from the general plane of the screening. In Figures 1 and 2 (and also in Figures 4 and this structural condition of such screening is apparent at the right-hand and left-hand edges of the cylindrical shade. In the shades herein illustrated I have shown bands of decorative material 4i) set into these depressed areas 39, such bands being preferably of color, brightness, and finish to contrast with the surface finishing of the screening itself. These bands may have a bright gold or silver finish, or any other finish desired. They serve to break up the overall appearance of the shade when the light source of the lamp is not illuminated, since at such time the vertical slats of the outside layer of screening present a surface appearance of rather barrel shaped form, broken only by the closely set vertical lineations presented by such slats. The bands break up this monotomy of appearance when the light source is not illuminated. The appearance of the shade is thenrepresented by the showing of Figure l, with the exception, of course, that the dotted elements of the lamp stand, and the light source bulb do not show through the shade. It is to be noted, however, that various finishes may be applied to the surface of the screening, such as Alodine finish or various colors and hues of finishes, various degree of brightness, reflecting quality, and other specifications of the finishes. When the light source is not illuminated the appearance of the shade is that produced solely by reflected light reaching the shade from its exterior.

Upon illuminating the light source an astonishing change in the appearance of the shade occurs at once. The appearance now presented is somewhat simulated by the showing of Figure 2. The vertical bars or ribs of the inner sheet of screening now appear as the somewhat shaded bands 41 extending vertically, and of widths corresponding roughly to the projected lateral dimensions presented when viewed from in front, or from a given location, as in Figure 2. This interior illumination also brings into view the successive horizontal slats of the inner sheet of screening, but restricted to that area of the ensemble over which the clearances between the vertical slats of the outside sheet of screening permit direct illumination to reach the eye of the observer. In Figure 2 I have simulated the appearance of these horizontal slat showings of the inner sheet of screening by the horizontal lines 42; it being noted that these lines, although black, really indicate locations of illumination reaching the observers eye through the clearances" between the outside sheet of screening, and which clearances register with slat openings of the inside sheet of screening. Actually the illumination thus transmitted through the two sheets of screening by direct transmission of light comprises a myriad of small dots of illumination scattered over the area or width of the shade over which the clearances of the outer sheet exist (when the shade is viewed by the observer from a given vantage point). However, due to reflections from the surfaces of the slats and other elements of the screening, the light thus direct ly transmitted is modified into a rather soft glow, pointed with small dots of brighter illumination, and with the brightness of the area so illuminated varying from substantially zero at each lateral edge of the area, to a maximum at the location where the direct illumination is greatest. The condition of such variation of brightness of this illumination from zero to a maximum and back to zero might have been indicated by variations in the widths of the lines 42 (it being remembered that such lines indicate locations of illumination, not darkness), but because of the size of the showing in Figure 2 such variations in the widths of such lines are not practically feasible. It is also noted that, due to imperfections in manufacture of the screening, and to manufacturing tolerances, etc., the lateral points of cut-01f and their locations vary somewhat from slat to slat, due to slight variations in the angles at which such slats lie with respect to the general plane of the screening. Accordingly, it will be noted that the lines 42 shown in Figure 2 do not all terminate rightwardly and leftwardly at exactly the same distance from the medial line, but rather they terminate at somewhat ragged limits which would be defined by ragged vertical lines extending through their successive terminal points. Such condition enhances the softness of the appearance of the shade when illuminated by the interior light source, and reduces the appearance of artificiality of the shade at such times.

In order to further enhance the beauty of the shade, especially when illuminated by the lamps source of light, I sometimes provide translucent or even transparent screens of suitable material within the shade, preferably directly against the inside surface of the inner sheet of screening. Such translucent or transparent screens may be various colors, shades, and hues, at the selection of the designer of the shade, and sometimes two or more such screens may be used over a selected area of the shade, of the same or different colors, to produce desired effects. Such translucent or transparent screens are not shown in Figures 1, 2 and 3, due to the fact that in Figure 3 the ring 27 of the frame overlies the thicknesses of such translucent or transparent screens. However, such forms of translucent or transparent screens are shown in the embodiments illustrated in Figures 4, 5 and 6, and

in Figures 15, 16 and 17, and will be described in connection with the showings of those figures.

Reference is next made to Figures 4, 5 and 6 in which I have illustrated another embodiment of the lamp shades. In this case use is made of the two sheets of screening, one inside of the other, and supported in juxtaposition according to the principles already discussed in detail. However, in the present case the outer or vertical slat sheet of screening is of less vertical dimension than the inner sheet, so that one or more sections, such as shown at 43 include only the horizontal slats. By so forming this section that its slats slant downwardly and outwardly of the shade, so that illumination from the interior of the shade is reflected downwardly and outwardly, the following functional effects are produced: Direct illumination through such section is either cut off from the eyes of an observer adjacent to the lamp and shade, or is greatly reduced so as not to be objectionable to one using such lamp and shade for reading or like purposes, and at the same time such section or sections 43 serve to direct, by reflection, much illumination downwardly to the text being read or examined by the obpresent, since most of the area of the shade includes the 13 combination double sheet screening previously explained in full detail.

Reference is also made to Figures 6 and 7, Figure 6 being a horizontal section taken on the line 6-6 of Figure 5, showing only the front -one-half of the shade cylinder. It will here be noted that the inner sheet of screening, 44 comprises chord sections lying at small an gles with respect to each other as already explained, such chord sections being bent on the lines ofthe bars or ribs 21 as shown in this figure. I have, in this Figure 6 also shown the transparent or translucent screen 45 of generally cylindrical form, set into the inner screen sheet, according to the principles already described.

In Figure 6, which is substantially double scale as compared to Figures 4 and 5, and shows the front onehalf of the horizontal section, I have indicated more or less generally, the area embraced by the clearances which are visible from either of two vantage points. In one case the vantage point is assumed to lie on the line 46, and for purposes of simplification it is assumed that the observer is far enough from the lamp shade to avoid the effects of angularity in shifting the line of vision from one side of the shade to the other. Then, when the line of vision is to the left-hand edge of the shade no clearances will be observed between the successive slats (formed on the angle to the general plane or tan-- gent to the surface of the curved shade at each point of observation), as the line of vision is shifted rightwardly until about the location of the line 47, at which time very narrow clearances will become apparent between the successive slats as the line of vision continues to shift rightwardly. These first clearances will be so small that diffraction effects will be apparent, produced by the direct illumination transmitted through such very narrow slots, or slits. As the line of vision continues to be shifted rightwardly the clearances will increase in width to a maximum and then further rightward shift of the line of vision will result in decrease of the widths of such clearances until the line ,of vision reaches about the location of the line 48. At that location such clearances will disappear, and further rightward shift of the line of vision will not produce any further clearance locations.

Now the distance between the limit lines 47 and 48 shown by the legend 49 may be termed the zone or area of direct illumination seen by the observer due to internal illumination of the shade. It is at once apparent that this area or zone is definitely shifted rightwardly from the direct line of vision 46, so that the effect produced to the observer is rather startling and unexpected. In fact this function, due to the use of the vertical slat screening in the combination herein disclosed, is due directly to the angling of the slats with respect to the general plane of the screening, or the tangent to the curvature of such screening at the location of the slats in question.

A further novel function which is produced by the foregoing relationship is as follows: If the direct line of vision be now shifted to one side, as for example rightwardly, from the line 46 to the'new line 50, it will be found that the leftward and rightward limits of the visible clearances shift from the line 47 to the line 51, and from the line 48 to the line 52, respectively. It will also be seen that during such lateral shift of the two limits of such clearances the total width of the area or zone of visibility of such clearances, shown by the distance 53 between the limit lines 51 and 52 is the same as before. It will also be seen that during such shift the lateral displacement of the medial line of the area or zone of visibility of the clearances still lies displaced laterally from the medial line of the shade as evident from examination of Figure 6.

In the foregoing analysis it has been assumed that the illumination reaching all of the clearances which are visible comes by parallel rays from an extensive area of light production or source. Actually such light source will generally comprise a lamp of rather limited area of light emission, such as an incandescent lamp; but due to the efiects of interior reflections occurring within the shade it is impossible to accurately delineate the exact limits of the visible clearances. It is true, however, as demonstrated by extensive use and tests of lamp shades embodying the features already discussed, that the area or zone of such direct illumination is substantially as hereinbefore described, and that such direct illumination varies substantially according to the laws already explained.

It will, of course be understood that as soon as the interior illumination of the shade ceases, as by turning off the light source, the appearance of the shade reverts to that appearance shown in Figures 1 and 4, wherein only light reflected from the outside surfaces of the screening is observed.

In all cases there is a large amount of illumination emitted from the surfaces of the screening elements when the light source of the lamp'is illuminated. Such reflections come principally from the surfaces of the slats, as these comprise by far the larger portion of the total exposed surface area exposed to direct illumination of the light'source, and in position to effect such reflections as will affect the effects hereinbefore explained. However, the combined effects of all such reflections are to produce a more or less uniformly distributed source of illumination reaching the spaces between the slats and thus affectting the appearance of the shade under effects of light source illumination.

In Figure-7 I have shown, more or less schematically, the general distribution of illumination radiated from the surface portions of the lamp shade at different locations across the width of. such shade. The lateral dimensions are shown by the horizontal displacements along the abscissa line 54, and the illumination strengths, such as lumens/sq.cm., are shown by the vertical distances or ordinal distances on the line 55. The general form of the curve of reflected illumination emitted by the lamp shade is shown by the curve 56. Such illumination rises from zero at the left-hand side, to a maximum substantially at the medial line of the shade, and falls again to zero at the right-hand side. It is also noted that this curve is generally rather flat as shown in Figure 7. It is further noted that this reflection component of illumination conforms to a curve of variation of strength which curve is substantially balanced at the two sides of the medial line 57.

In Figure 7 I have also shown by the curve 58 the typical manner in which the strength of direct illumination coming through the clearances varies as the eye of the observer sweeps across the lamp shade illuminated from inside, and according to the principles already discussed. The two limit lines are shown in this figure, and it appears that the direct illumination rises from zero at one such line to a maximum value at the location 59, and then falls again to zero at the other side of the area or zone of such direct illumination. This is in accord with the disclosures already made herein.

In Figure 7 the curve 69 shows the summation of the two curves 56 and 58 for that area or zone which corresponds to the light coming through the clearances. This combined curve shows very startlingly the effects of the direct illumination permitted by the clearances between the successive slats. This effect or function is a distinctive feature of the use of vertical or substantially vertical slatting, with the slats formed at an angle to the general plane of such screening, or to the tangent to the curve of the shades surface at each slat location, such angle being other than a right-angle.

In Figures 15, 16 and 17 I have shown an embodiment of my present invention in which the same is incorporated in an advertising unit or novelty. In this case the double sheet screening feature is incorporated in a semielliptic element 61 having its side edges seated into flanged brackets 62 and 63 which are connected to a back plate 64 to which such brackets are connected by lugs 65 extended through the back plate and connected thereto in convenient manner, the back plate being provided with slotted openings 66 to accommodate such lugs. The front or exposed surface 67 of such back plate may be provided with a surfacing of selected color and finish, with the exception of the area 68 to the rear of the element 61. This area 68 may be provided with a polished and reflecting surface to better throw the illumination from a light source 69 forwardly and against the inner surface of such element 61. The bottom of the space enclosed by the element 61 is open to allow direct illumination of the area below the element 61 by light coming from such light source. An advertisement such as shown at 70 may be provided on the backplate 64 so that it will be directly illuminated by the downwardly reaching light rays from the light source when illuminated.

Detailed description of the double sheet element 61 is not needed since the principles already explained apply to such double sheet element.

I claim:

1. As a new article of manufacture, a lamp shade of contour to at least partially enclose a light emitting element, a first defined surface element of said shade comprising an element of contour developed by a straight line moved parallel to itself in a curving direction, and a second defined surface element of said shade being of polygonal form and comprising a series of fiat elongated rectangular panels having the longer edges of the proxirnate panels connected together, and said connected edges of the panels being parallel to each other, and parallel to said straight development line of the first defined sur face element, each surface element of said shade comprising a sheet of screening formed of sheet metal to provide parallel louvre supporting bands lying in the surface of such sheet, and each such sheet of screening including a plurality of parallel zones between the succes sive louvre supporting bands of such sheet, each zone including a multiplicity of straight narrow elongated louvres extending across such zone between the bands defining such zone and at right angles to said bands, and the central line of said zone extending normal to the louvres of such zone and parallel to the bands defining such zone, the ends of the louvres being connected integrally to the proximate edges of the bands, and the central lines of the louvres lying parallel to each other in the surface of the zone containing such louvres at successive equal spacings of the louvres from each other, and all of the louvres being formed and lying in surfaces twisted on the aforesaid central lines of such louvres with respect to the surface of the zone containing such louvres, the angles of twist of all of the louvres of each zone being substantially the same and the surfaces of the louvres of each zone being parallel to each other, the first defined surface element of such shade comprising one sheet of such screening having the bands and the central lines of the zones of said screening sheet extending in the direction of and conforming to the curvature of said first defined surface element and having the bands of such screening sheet curved to conform to said curvature and having the louvres of said screening sheet extending parallel to said line of surface development and being uncurved, and the second defined surface element of said sheet comprising another sheet of said screening having the bands and the central lines of the zones of said second screening sheet 1 extending in the direction of said line of surface develop-- ment and having the louvres of said second screening sheet uncurved and extending in direction at right angles to the louvres of the first screening sheet and parallel to lines of tangency to the curvature of the proximate portion of the first defined screening sheet, both of said screening sheets having their proximate surfaces in close proximity to each other and in contact with each other at the locations of connection of the louvres of the screening sheet of the second defined surface element with the bands of such screening sheet, said screening sheets being separated from each other at locations between said locations of contact.

2. An article of manufacture as defined in claim 1, wherein the curving direction in which said line of development is moved comprises a circular arc.

3. An article of manufacture as defined in claim 1, wherein the curving direction in which said line of development is moved comprises a non-circular arc.

4. An article of manufacture as defined in claim 1, wherein the first defined screening sheet of the shade provides the convex surface of the shade, and the second defined screening sheet of the shade provides the concave surface of the shade.

5. An' article of manufacture as defined in claim 1, together with a sheet of translucent light transmitting material in contact with the concave surface of the shade.

6. An illumination device comprising in combination an artificial light source for emitting substantially radial light rays, a composite tubular double screen comprising a first and a second screen for both passing and deflecting portions of said light rays, and means for supporting both light source and composite screen, said means fixedly positioning said light source on the axis of said composite, double screen, said first screen comprising a single piece of thin sheet material with a great multiplicity of uniform, integrally pierced, fixed, narrow, longitudinal louvres, said louvres being spaced from each other and arranged parallel with each other longitudinally in a plurality of parallel panels, said louvres being integral with and at right angles to narrow supporting ribs between adjacent panels, said panels extending throughout the screen and having their louvres twisted at their ends and their faces sloped with openings to pass and faces to deflect light rays outwards from said light source, said first screen being bent along the axes of its narrow ribs to form a polygonal tube, and said second screen being of a single piece of thin sheet material similar to said first screen, except being curved along its narrow ribs to circumscribe said first screen, and mounted in proximity to said first screen, and with its louvres non-parallel with those of said first screen.

References Cited in the file of this patent UNITED STATES PATENTS 1,447,859 Johnson Mar. 6, 1923 1,619,720 Gordon Mar. 1, 1927 2,435,786 Klosek Feb. 10, 1948 2,601,034 Lee June 17, 1952 2,670,431 Bullock Feb. 23, 1954 2,683,800 Tradelius July 13, 1954 2,761,959 Kunins Sept. 4, 1956 FOREIGN PATENTS 401,506 Great Britain Nov. 16, 1933 

